To use a credit card on Uber, you must first add it as a payment method within the app's "Wallet" or "Payment" section. Tap your account icon, select "Wallet," and then choose "Add Payment Method." You will need to enter your card number, expiration date, CVV code, and the billing zip code. Once the card is saved, it becomes your default payment option for future rides. Before you request a trip, you can confirm which card is being used by tapping the payment icon just above the "Confirm" button on the ride-request screen. At the end of your journey, the fare is automatically charged to the card on file, including any tip you choose to add through the app. You can also toggle between different cards or use digital wallets like Apple Pay or Google Pay if you have linked them to your Uber account.